Our research has as its goal the determination of the factors controlling molecular transformations of biologically significant moieties upon ultraviolet irradiation. We are also developing the ability to effect selective transformations of molecules which then can be used as a general tool in biological systems. Our present stage of development in research has brought us to direct determination of the rates of energy dissipation and of reaction of singlet excited states. This allows us to correlate the rate of molecular transformations with structural features. We are pursuing parallel studies dealing with triplet multiplicity species. In our research our approach is to design model systems incorporating the molecular grouping of interest and then to see how the reaction and decay rates depend on structure. Along with this we are investigating excited state transformations using other information such as reaction stereochemistry. Another goal of our research is finding new types of photochemical transformations which will prove of general utility.